Fuel-injecting nozzle



Nov. 2 1926. 1,605,635

H. JUNKERS FUEL INJ'ECTING NOZZLE Filed Nov. 1v. 1921 Patented Nov. 2,1926..

UNITED STATES 1 .L\'l`1-:NToF-FICE.

" HUGO JUNKERS, 'OF DESSAU, GERMANY.

FUEL-INJECTING NOZZLE.

.applic-ation mea Noveinber 17, 1921,-seria1 Nn. 515,995, and 'n1Germany January-1o, 1921.,

My invention relates to internal combustion engines and moreparticularly toa the el nozzles of such engines in which liquid fuel isinjected by solid injection, that is, 5 without the assistance of airand at high pressure, into a charge of compressed air. In'such injectiondevices the fuel, in order to effect the vaporizatioii required forcomlete combustion, must be injected at a very l0 liigh pressure as arule at several hundred atmospheres. Such high pressures necessitate avery lcareful tightening of the parts supplying the fuel, and allpossibility of the formation of air pockets must be obviated asotherwise the injection becomes irregular and the operation of theengine unreliable.

In the injection devices as heretofore constructed, a nozzle body wasemployed as a rule, having a wide bore and a needle arranged within saidbore and partly filling it, so that the fuel could pass to the point ofinjection through the annular space between the nozzle body and theneedle. This construction involves the drawback that the body of thenozzle is deformed in conse-- quence of the high pressure of the fuel sothat it is diliicult to keep it permanently tight. Further, the velocityof the fuel is comparatively slow on account of the comaratively greatcross-sectional area so that bubbles of air and gaswill readily form.

In accordance with my invention I obviate these drawbacks by injectingthe fuel through the needle which is to this end provided with suitablefeed passages. These passages open in the vicinity of the injectionpoint within the tightening faces between the needle and the nozzle bodyso that the nozzle body is not strain d by the inner pressure of thefuel.

In this arrangement it is further possible to connect the fuel supplypipe directly to the needle so that the fuel is conducted at highvelocity to the opening of the nozzle l.45 without any change ofdirection and crosssectional area.

In some cases, it is desirable that the end of the needle adjoining thecombustion cham-k ber should be readily exchangeable, for instance wherefuel is used which has a tendency to form incrustations or which exertsa chemical destructive laction on the metal. The needle is preferablymade in two parts dle against the tighteningface of the nozzle the outerpart of the needle,

body. The tightening between the two parts v of the needle is leffectedin such manner that the bore extends uniformly from one Ipart to i theother and no extensions and cavities are formed at the joint where airbubbles or the like might collect.

en assembling and forcingthe parts of the nozzle against the tighteningsurfaces, the2 parts of the nozzle should be prevented from turningabout their axes as the ejection openings ofthe nozzlehave .to take up adefinite position inl relation tothe axis of the cylinder and which isdetermined by the form of the fuel jet. Furthermore the fuel supply pipeshould be protected against twistin when screwingdown the nozzle, asother'wlse the supply pipe might be damaged. Therefor, that part of theneedle which is connected with the supply pipe, is preferably so formedthat it is free `to when the means for tightening the nozzle arescreweddown but is unable to turn.

In the`drawings affixed to this specification and formingl part thereof,an embodiment of my invention is illustrated dia lammatically by way ofexample. In the rawingsj Fig. 1 is a longitudinal section of. thenozzle,

Fig. 2 is an elevation of the nozzle body,

Fig. 3 is an elevation of the needle,

Fig. 4 is an end elevation of the needle,

Fig. 5 is a section on line V-V of Fig. 1.

`The novel device comprises a nozzle body b screwed into the wall a ofthe workingcylinder by means of a thread m. In an laxial bore of thenozzle body b a needle in move axially ofpart [dis `tightened on thenozzle body by means Tof a conical surface lo. The ejection ports g, ZLbranched oif the central bore open into the cone and communicate withnarrow channels z' and j formed in this surface. The fuel jets ejectedthrough these passages at high velocity meet at the apex of the cone c,whereby avery intimate mixture of the fuel is obtained.

Owing to the ports g and Zi, opening into the tightening surface formedin cone k the fuel is prevented from entering the spaces between theneedle (Z and the body b. Up to the point of ejection the fuel flowsexclusively in the narrow bore f at high Velocity so that air bubblescannot accumulate. At the same time the nozzle body Z) is relieved ofall liquid pressure. The cone c need be tightly applied against its seatin the body b only in the vicinity of ports g, h and channels z', Thearea of the ktightening surface between the needle and the body Z) isthereby reduced while the ing surfaces is increased and the reliabilityof the tightening is improved correspondingly.

The fuel supply pipe Z is inserted and brazed in the outer end of part eof the needle. The bore in the yvasher c corresponds exactly to the boref of the needle so that the fuel is conducted in an even path from thesupply pipe Z to the ejection ports The outer end of the body b isthreaded and provided with a cap nut n which exerts axial pressure onparts d and e and forces the tightening surfaces of cone 7c against thecorresponding faces of body b. In order to prevent turning of the needleparts d, e and twisting of the supply pipe Z when screwing down orunscrewing cap nut it, projections u are provided on an enlargement wformed on part e which are adapted to engage/'con responding recesses a(Fig. 2) in the threaded outer end of the nozzle body b, so that thepart e is free to move axially relation to the body ZJ but not to turnin I wish it to be understood that I do not desire to be limited to theexact details of construction shown and described for obviousmodifications will occur to a personA skilled in the art. y

I claim 1. Nozzle for liquid and gaseous fuel in- ]ection and the likecomprising an outer body having a boring conicallyv'contracted at oneend and an opening at the apex of the cone, a needle fitting by aconical end surface into the cone of said boring, said needle having anaxial channel ending short of said conical end, branch channelsextending from said axial channel and opening into said conical endsurface at points specific tightening pressure at the tighten-- rearpart, said front somewhat distant from the base of said conical end,grooves inl said conical surface extending from said branch channels tothe apex of said conical surface, fuel supplying means directlyconnected to the said axial channel of said needle and separate meansarranged near the 'outer end of said body for tightening together saidcones.

Q. Nozzle for liquid or gaseous fuel injeetion and the like, comprisingan outer body having a boring conically contracted vat one end and anopening at the apex of the cone, a needle terminating in a conical endsurface and having near said end a materially smaller diameter than saidboring, said needle being inserted in said boring with said end surfacetightly applied against the conical inner wall of said boring, saidneedle having an axial channel ending short of said conical end andbeing connected with said conical end surface by branch channelsextending from said axial channel and opening into said surface atpoints somewhat distant from the base of said conical end, grooves insaid lconical surface extending from said branch channels to the apex ofsaid conical surface and means arranged near the outer end of said bodyfor tightening said cones together.

3. Nozzle for liquid or gaseous fuel injection and the like, comprisingan outer body having a boring conically contracted at one end and anopening at the apex of the cone, a needle in two parts, a front partterminating in a conical end surface, a rear part and fuel supplyingmeans directly cenneeted to said rear part, said needle being insertedin said boring with said end ysurface tightly applied against theconical inner wall of said boring, said needle having an axial channelending short of said conical end and being connected .with said conicalend surface by branch channels extending from said axial channel andopening into said surface at points somewhat distant from the base ofsaid conical end, grooves in said conical surface extending from saidbranch channels to the apex of said conical surface and means acting onthe rear part of said needle for pressing said conical end surfaceagainst the conical inner wall. of said bod 4. Nozzle for liquidv orgaseous fuel injection and the like, comprising an outer fbodyhaving aboring conically contracted at one end and an opening at the apex of thecone, a needle in two parts, a front .and part terminating in a conicalend surface, said needle being inserted in said boring with said endsurface tightly applied against the conical inner wall of said boring,said needle having an axial channel ending short of said` conical endand being connected with said conical end surface by branch channelsextending from said axial channel and opening into said surface atpoints somewhat distant from the base of said conical end, grooves insaid conical surface extending from said 5 branch channels to the apexof said conical surface and means acting on the rear part of'said needle:for pressing said conical end surface against the conical inner Wall ofsaid body, said rear part and said body being interlockedA forpreventing relative 'i0 circumferential movement.

In testimony whereof I affix my signature.,

Y HUGO JUNKERS.

